Although frequently used in aerosol therapy, Inhaler Extension Devices (spacers) have undergone little controlled evaluation or comparison. Present designs are inefficient and display wide variability in the dosage delivered. The viability of these devices with non-chlorofluorocarbon (CFC) propellants is also under question. Many of these problems result from inadequate knowledge of flow dynamics within the spacer. The goal of the proposed study is to design an optimal spacer that provides maximum dose with minimal variability for the treatment of pediatric asthma. Both numerical and experimental investigations will be pursued under consultation with a clinical user (UMDNJ Division of Pediatrics) and an industrial manufacturer (DHD Healthcare) of spacers. The Phase I study will commence with state-of-the-art computational fluid dynamics analyses coupled with in-vitro experiments of selected commercial spacers. Based on the results of this study, a set of potential specific modifications to a baseline spacer design will be compiled. The alternative designs will be assessed using CFD, and the most promising design will be chosen for prototype manufacturing. Improvement in device performance will be established through experimental comparison with commercial alternatives. Phase Il will involve further computational design optimization followed by in vitro experiments, fabrication and testing of clinical grade spacers. PROPOSED COMMERCIAL APPLICATIONS: The improved spacer design(s) developed in this study will have a direct impact on the 5 million children diagnosed with asthma. This will be accomplished through an efficient inhalation system with minimal local side-effects. The device will be marketed and/or licensed to present spacer manufacturers or pharmaceutical firms such as Glaxo, Pfizer, Schering- Plough, etc. who in turn will offer the device to patients and healthcare professionals. This approach can also be extended to spacers for other respiratory applications (inhalable insulin, etc.).